Re: [PATCH v2 19/21] treewide: add checks for the return value of memblock_alloc*()

Christophe Leroy
2019-01-31T06:07:46Z

Le 21/01/2019 à 09:04, Mike Rapoport a écrit :
> Add check for the return value of memblock_alloc*() functions and call
> panic() in case of error.
> The panic message repeats the one used by panicing memblock allocators with
> adjustment of parameters to include only relevant ones.
>
> The replacement was mostly automated with semantic patches like the one
> below with manual massaging of format strings.
>
> @@
> expression ptr, size, align;
> @@
> ptr = memblock_alloc(size, align);
> + if (!ptr)
> + panic("%s: Failed to allocate %lu bytes align=0x%lx\n", __func__,
> size, align);
>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> Reviewed-by: Guo Ren <ren_guo@c-sky.com> # c-sky
> Acked-by: Paul Burton <paul.burton@mips.com> # MIPS
> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390
> Reviewed-by: Juergen Gross <jgross@suse.com> # Xen
> ---

[...]

> diff --git a/mm/sparse.c b/mm/sparse.c
> index 7ea5dc6..ad94242 100644
> --- a/mm/sparse.c
> +++ b/mm/sparse.c

[...]

> @@ -425,6 +436,10 @@ static void __init sparse_buffer_init(unsigned long size, int nid)
> memblock_alloc_try_nid_raw(size, PAGE_SIZE,
> __pa(MAX_DMA_ADDRESS),
> MEMBLOCK_ALLOC_ACCESSIBLE, nid);
> + if (!sparsemap_buf)
> + panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%lx\n",
> + __func__, size, PAGE_SIZE, nid, __pa(MAX_DMA_ADDRESS));
> +

memblock_alloc_try_nid_raw() does not panic (help explicitly says: Does
not zero allocated memory, does not panic if request cannot be satisfied.).

Stephen Rothwell reports a boot failure due to this change.

Christophe

> sparsemap_buf_end = sparsemap_buf + size;
> }
>
>